This invention relates to the fields of electronic image processing and stereoscopic image analysis.
Stereoscopic imagery in which physically displaced views of the same image are presented simultaneously for conveying the illusion of depth is well known in the art. The patent of A. Rosenfield, U.S. Pat. No. 2,910,910 is an example of stereo imaging wherein two slightly displaced photographs of the same terrain are viewed simultaneously using red and green filtering for the purpose of automatically plotting terrain contour maps. The Rosenfield patent also shows the combination of stereo imaging apparatus and digital computing apparatus.
Another example of stereo imaging apparatus is found in the patent of J. W. Knauf, U.S. Pat. No. 3,464,766 wherein a stereo image is viewed by a person with the aid of a synchronized shutter which alternates the views received by the left and right eye.
The U.S. patent of J.E. Ihms, U.S. Pat. No. 4,133,602 is a recent example of stereo image optical apparatus and discloses the use of a single photographic medium for recording the two images needed for a stereoscopic view. The Ihms patent includes an interesting discussion of the history and state of the art in one portion of the stereoscopic image technology. Another recent example of stereo imaging apparatus is found in the U.S. patent of H. J. Wehrli, U.S. Pat. No. 4,290,694 wherein an apparatus for detecting changes between two photographic views of the same image is disclosed. The Wehrli patent also includes a listing and discussion of prior art in stereo imaging. Another recent example of stereo imaging apparatus is the U.S. patent of A. P. Colvocoresses, U.S. Pat. No. 4,313,678 wherein an apparatus for determining height or elevation of a photographed object is disclosed. The Colvocoresses patent contemplates the use of satellite photography and the measurements of elevation on a terrestrial body.
The U.S. patent of G. G. Langdon et al, U.S. Pat. No. 4,225,861 is of interest with respect to the present invention since it discloses the use of digital electronic processing to change a photographic image into an image having new color components for analysis; the changes being made in response to dimensional elements from the original photograph. The Langdon et al patent does not contemplate the use of stereoscopic viewing or the changing of image element locations however.
The International Imaging Systems (I.sup.2 S) Model 70E processor used in the preferred embodiment of the invention is described in several application publications which are listed below for both the purpose of incorporation by reference and for consideration as prior art in the field of image processing.
1. "Applications of Digital Image Processing Techniques and Hardware to Regional Growth Modeling" by Ted Driscoll, Proceedings of the American Society of Photogrammetry Vol. 1 45th Annual Meeting, Mar. 18-24, 1979, Washington, D.C. The bibliography and Technical appendix of this article covering the Model 70 processor are of additional interest. PA0 2. "A Low Cost Transportable Image Processing System" by John R. Adams and Edward C. Driscoll, First ASSP Workshop on Two-Dimensional Digital Signal Processing, Oct. 3-4, 1979 Lawrence Hall of Science, Berkley, Calif. PA0 3. "High Speed, Hardware Classification of Multispectral Imagery duplicated in a General Purpose Image Display" by Edward C. Driscoll, Jr. of I.sup.2 S, Journal of Applied Photographic Engineering June 1982 Vol 8 #3. PA0 4. Evolution of Image Processing Algorithms from Software to Hardware by Ted Driscoll and Chris Walker of I.sup.2 S. Proc. of Society of Photooptical Instrumentation Engineers, Vol 271 February 1981 Paper #17. PA0 5. New concepts in Display Technology by John Adams and Robert Wallis, Computer, August 1977 p61-69.
The inventors of the present invention also have a copending U.S. patent application for another invention which uses the Model 70E I.sup.2 S image processor. This application is U.S. Ser. No. 06/556,861 filed Dec. 1, 1983, and contains descriptive material relating to the Model 70E processor; the contents of this application are hereby incorporated by reference.